Circuit-breaker.



F. L. SESSIONS.

GIRGUIT BREAKER. APPLIOATION FILED 001'. 9, 1905.

1 ,072,1 78. Patented Sept. 2, 1913.

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CIRCUIT BREAKER.

APPLICATION I'ILED 001'. 9, 1905.

Patented Sept. 2, 1913.

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CIRCUIT BREAKER.

APPLICATION FILED 0013.9, 1905.

Patented Sept. 2, 1913.

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UNITED srArEs PATENT oEEIoE.

FRANK L; SESSIONS, or COLUMBUS, 01110 Assmnon, BY iaEsNE ASSIGNMENTS, 'ro THE JEFFREY MANUFACTURING COMPANY, A CORPORATION or OHIO.

CIRCUIT-BREAKER.

Specification of Letters Patent. v

Patented Sept. 2, 1913.

Application filed October 9, 1905. Serial in. 282,042.

7 b (ZZZ whom it may concern:

Be it known that I, FRANK L. SESSIONS, a citizen of the United States, residing at C0- lumbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Circuit-Breakers, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to improvements in circuit breakers, the devices by which electric circuits are opened and closed as de sired.

The object is to provide a circuit breaker which will be capable of opening circuits which carry powerful currents, without disastrous results from the arcs which are formed. p

Figure l is a front view of a circuit break-v ing device embodying my improvements. Fig. 2 is a horizontal section on the line 2-2 of Fig. 1. Fig. 3 is a central transverse vertical section on the line 3 3 of Fig. 2. Fig. 4 is a vertical sect-ion taken on the line 4.4i of Fig. 3. Fig. 5 is a'vertical section taken on the line 55 of Fig. 3. Fig. (3 is a diagrammatic View showing the path of the current across the brushes and around the magnet coil, and also showing the path taken by the are when it is blown out by the lines of force of the magnet.

Among the objects ofthe invention are these, namely, to provide a cylindrical switch which can operate accurately in relation to the terminal brushes; to insure that this switch shall have its contact surfaces maintained smooth and not affected by the flame or heat of the arc; to provide means for accurately adjusting the magnetic tripping devices so that the breaker can be set for any predetermined strength of current, within limits, and to provide a Visual indi cator to indicate at any time the strength of current requisite to automatically operate the circuit breaker.

A casing is provided to support and cover the operative parts of the device, ithaving a back part K and a front part K. These are, each of them, box-like in conforn'iation. Their open sides are adapted to be fitted together, edge'to edge, the plane of contact being shown at is. They are, firmly fastened.

together by means of the screws or bolts A part of the lower side of each of these sec' tions of the casing is cut away so as to form a slot or passage as shown at K to permit the movement of the lever of the circuit breaker. The rear part K of the casing is made of diama 'netic material, such as zinc. The front part? of the box or casing may be made of similar material, though it is not ofas much importance, and may be of iron. In the frontwall of the front part K of the casing is a slot K for a purpose to be described. At a, a, there are apertures in the side walls for the introduction of the terminal wires of the circuit.

The rear part K of the box or casing is secured to a suitable support as at M by means of screws such as shown at 70 70 E This part K supports the metallic part F, which constitutes one of the pole pieces of the magnet to be more fully described, there being screws or bolts as at f, J, for fastening it to the back wall of the rear part K of the box.

F is a core piece which is secured in a threaded aperture in the pole piece or plate F. At its front end core piece F has a flange or expanded head'F in the lower part of which there is formed a transverse .pivo-t aperture. F represents the second pole piece of the magnet. It is pivotally connected to the core F 2 by means of the pivot pin f passing through the aforesaid aperture in the bottom of the flange F and through ears f on the hinge piece F. The magnetic circuit will now bepnderstood to be from the core piece F to the pole piece F, thence across to the pole piece F and back to the core.

The coil of the magnet is indicated at H The lines of'force of this magnet are utilized for blowing out the are which tends to form bctween'the brushes of the stationary terminals of the circuit and which I will now describe.

A indicates one of the brushes, A the other.

B is the rotary switch piece which is adapted to be turned around an axis in such way as to electrically connect the brushes A and A by contacting with both of them. As shown, it consists of a segment of a ring of metal; It is rigidly secured to a handle device indicated as a whole by C. This comprises the insulating handle 0 which projects below the casing and is adapted to be grasped by hand; also a pivoted yoke having the legs C C; and also the binding or clamping bolt C". The switch. piece B is insulated from the handle C and from the legs 0 C of the fork by meansv of the insulated washers 0, 0 and the bushing 0 The binding bolt C extends lengthwise through the handle C, and has its head C seated in a cavity in the outer end of the handle, which cavity-is closed by the insulating piece C. These parts, to-wit, the handle, the switch segment B and the fork C C are hinged to the core piece F the leg (3 of the fork being secured by the pivot f and the leg 0 by the pivot f. The latter pivot passes through the aperture f in the movable pole piece'F.

It will be observed that the core F sets out or away from the casing walls; and that the arms C, C of the handle, while within the casing, are ivoted to the ends of the core piece outsi e of or beyond the planes of the coil H thus making a very simple and compact arrangement of parts, and one that is easily accessible upon the opening of the casing. f

It will be seen that by grasping the handle C the switch segment B can be turned around its axis in such way as to move into and out of contact with the brushes A, A. A spring D tends to normally turn the ban: dle and the switch segment to the off position, this spring being secured to the easing at d, and to an extension E on the leg 0 of the fork. This extension has a shoulder at 6 serving as one element of a catch,

the other element being a latch dog E,

which is pivoted to the casing at 6. When the handle C is thrown in suchway as to bringthe switch segment to the on position, the latch E drops into position in front of the shoulder 6 and the spring D, though under. tension, is prevented from opening the switch.

When the current passing through .the circuit exceeds a predetermined quantity the circuit breaker is automatically opened, as follows: The swinging pole piece F is normally held in its outermost position by a spring G, which is riveted at g to the casing wall, and'at its upper end fits loosely under the pin G on the pole piece. The tension of the spring G is adjusted for the desired amount of current. NVhen this is exceeded there is an increase in the energizing of the magnet F, F, F and the swinging pole F overcomes the tension of the spring G and moves toward the opposite pole F. This motion is utilized to move the latch E so that the spring D will be free to move the switch ringB and break the circuit. The pole piece F is formed with an arm f which extends outward from the line of the axis at P, and the end of this arm lies under a vertical sliding pin or rod f which is mounted in guides e on. the casing wall. The upper end of this rod or pin f lies immediately under a lug "on the latch bar E When the pole piece F swings inward its arm f lifts the latch piece E and releases the fork lever so that the spring D can instantly draw the switch segment B away fromv the brush A and open the circuit. When this separating of the part B from the part A occurs, an arc is formed between the parts A, A. Under the action of the lines of force of the magnet this are is compelled to travel, or is blown, outward as indicated by dotted lines in Fig. 6. Each of the brushes A and A has two active surfaces, one at a and the other at a The surface at at acts in conjunction with the switch part..--B, and the surface at a acts to carry the arc. The surfaces of, a it will be seen, diverge from each other, and consequently the arc is.

rapidly elongated and very quickly dissl: pated. By having the are located between these surfaces a a the surfaces a are saved vfrom burning. These parts, namely,

the switch segment 13, and the brushes A,-.

A are all mounted in an insulated chamher or chimney. It is formedby the rear insulating wall K the front wall K and the side walls K K and at K insulation is interposed between the core F and the coil H The pole pieces F and F are situated outside of this insulating cha mher. It is open at the top as shown at 10.- 'The heated air and gases can readily escape to the atmosphere, the direction taken by the arc in approaching this open top being shown in Fig. 6, where the dotted lines at K, K indicate, approximately, the positions of the insulating walls.

P indicates the terminal portion of the conductor over which the current may be regarded as traveling in its approach toward the circuit breaker, and P indicates the terminal part of the conductor for the current as it leaves the device.

H indicates a binding post for the in-lead P, and H a binding post for the out-lead. The brushes'A, A are yieldingly mounted upon spring arms or plates A A The lower end of the arm A is secured-to 'an extension ,h of the binding post H, ,and

the arm A. is secured to an extension if of a binding post or terminal holder H. The current entering along the conductor P passes over the arm A to the brush A, and thence through the switch segment B, when the latter is in the position shown in Fig. 5, to the brush A, thence along the arm A to the binding post II. From this it travels to the coil H over the terminal h, and "from the coil along the terminal h to the binding post H whence it passes out on the conductor P.

The binding posts H and H are firmly secured-to the'insulating plate K The path of the current is indicated by the arrows in Fig. 6.

The spring G which normally holds the.

hinged pole piece F in its outermost position can have its tension varied as required. One way of accomplishing this is illustrated in the drawings. At points above the fastening device 9 the spring has a slot 9. Through this is passed a screw G the head g lying inside of the spring G. The shank of the screw passes through the slotK in the face plate of the casing section K; The outer threaded end of the screw G is provided with a clamping nut g". If this be loosened the screw G can be moved up or down in the slots K and g. If itbe adjusted to relatively higher points it will require greater force to bend the spring G inward, and vice versa.

9' is a bushing having flat sides fitted to the sides of the slot K, so that it can be moved vertically, but cannot be rotated. It has a flange bearing against the outer face of the cover, and from this flange projects a pin g The nut g has several notches g, each adaptedto engage with the pin IVhen sufficient effort is exerted upon the nut it can be turned, but not until the spring G has been forced outward far enough to permit the nut to leave the surface of the flange g, and pass over the pin 9 At G there are graduations along the Plot K, these indicating the quantity of current required to trip the circuit breaker with the different adjustments of the screw G The flange 9 is provided with an index projection to indicate accurately the position of the adjusting screw.

It is sometimes necessary to manually open the latch Ev and release the switch lever so that the spring D can act upon it. This is done by means of a push pin L mounted in the front part of the casing and adapted to engage with the upper end of the swinging pole piece F. By pushing in upon this pin L the pole piece F is moved to its inner position, and in doing so its trip arm f thrusts the pin f upward, which, in turn, lifts the latch E in the way. above described.

By examining Fig. 5 it will be seen that.

the switch segment B, when in the on position, has an end part b which projects considerably beyond the contact surface a of the brush A. The purpose of this extension to the switch segment is that it shall carry the are when the circuit is broken or opened, that is, when the switch segment B is escaping and moving away from the brush A; whatever burning of the metal of the movable segment takes place will be experienced bythis projecting part b,and the contact portions of the outer surface of the segment will not be roughened by the burning action, but will remain smooth, so as to have smooth contactwith the brushes over the whole contact surface.

What Lclaim is:

1. In a circuit breaker, the combination of the supporting device, the magnet pole piece secured to the supporting device, the magnet core, the movable pole piece supported on the core, the insulating chamber said switch segment pivoted to the ends of the magnet core, substantially as set forth,

3. In a circuit breaker,the combination of the magnet pole piece, the stationary support therefor, the magnet core, the movable pole piece, the terminal brushes between the pole pieces, the rotary switch segment en gaging with the brushes, and the yoke-like carrier for the switch segment, the legs of said yoke being pivotally supported 011 the longitudinal lines of the magnet core, substantially as set forth. c

4. In a circuit breaker, the combination of stationary'terminal brushes of an electric circuit, an oscillatory switch "piece between said brushes, a magnet core having its axis parallel to the axis of oscillation of the switch piece, opposite-magnet pole pieces arranged adjacent to and onopposite sides of the said brushes, whereby the lines of magnetic force passing between the pole pieces will operate to blow out'an are that may form between the brushes, one of the said pole pieces being movable toward or from the other, means for providing an electric circuit around the core, means for breaking such circuit, and a lock for circuit breaking means arranged to be released by the said movable pole piece,substantially as set forth.

In a circuit breaker, the combination of terminal brushes, a rotatable switch segment arranged to make bonnection between the brushes and a stationary magnet for blowing out the 'arcs between the brushes, the said magnethaving two pole pieces, a stationary core and a coil surrounding the core,

the said core, coil, switch segment and the contact faces of the brushes being arranged in concentric relation to each other and beine; situated in the same transverse plane, substantially as set forth.

6. In a circuit breaker, the combination of the magnet coil, a core within the said coil, a pole piece fixed with respect to the core, a second pole piece movable with respect to the core, a switch'segment rotating around the axis of the magnet coil in the single air gap between the pole faces of the said pole pieces, terminal brushes also mounted in the ment, brushes and ma with the brush terminals terminal brushes mounted on yielding supand the magnet coil, said switch segt coil being all located within the said msulating chamber, substantially as set forth.

- 8. In a circuit breaker, the combination of ports,

the chamber having insulating walls, the

magnet core extending across said chamber,

the magnet coil, the rotary switch segment,

the terminal brushes, the said coil, switch and brushes being arranged concentrically within the said insulating chamber, the magnet pole pieces outside of the insulating chamber, and the support for the switch segment situated outside of the said chamber and mounted to rotate on the axis of the magnet core, substantially as set forth.

9. In a circuit breaker, the chamber hav-v ing. insulating walls, the magnet core extending across said chamber, the magnet coil, the rotary switch segment and the terminal brushes all being within the said chamber, the stationary pole piece secured to the core and arranged to support the aforesaid pa s, and the movable pole piece opposite to the stationary pole piece, substantially as set forth.

10. In a circuit breaker, the combination of the'chamber having insulating walls, the magnet core extending across the chamber, the magnet coil, the rotary switch segment, and the terminal brushes all situated within the said chamber, the movable pole piecemounted on the core, and the stationary pole piece arranged to sup ort all of the aforesaid parts, substantial y as set forth.

. 11. In a circuit breaker, the combination of the circuit, of the movable switch piece B, the-supporting yoke C C the handle G, means for binding together the switch-piece, the yoke and the handle, and means for insulating the switch piece from the yoke and the handle, substantially as set fortha -12. In a circuit breaker, the combination of the chamber having the insulating walls K K", the magnet having the core F passing through the insulating chamber,the pole piece F rigidly secured to the core, and se-' cured to a stationary support, the hinged polepiece F, the pole pieces F and F being outside of and adjacent to the insulating walls K}, K", the magnet coil the brush terminals A, A and the switch segment B all between the insulating walls, means for automatically moving the segment B around the axis oft-he core F a lockfor the last said means, and the trip device for the lock actuated by the polepiece F substantially as set forth.

13. In a circuit breaker, the two part box or casing, the insulating chamber, the circuit terminals and the rotary switch segment within the insulating ,chamber, the magnet having its pole pieces arranged within the casing, all supported on the inner section of the casing, and the outer section being separable from the inner, in the plane of the insulating chamber, substantially as set forth.

14. In a circuit breaker, the combination with the insulating chamber, the magnet 'coil, the terminal brushes, and the rotary switch segment, all within the insulating chamber, of the two magnet pole pieces outside of the insulating chamber, and the twopart casing inclosing the said insulating chamber and pole pieces, one part of said casing being formed of diamagnetic material, substantially asset forth.

15. In a circuit breaker, the combination of the insulating chamber, the magnet coil, the terminal brushes, and the rotary switch segment, all within the insulating chamber, of the pole pieces outside of the insulating chamber, and the two-part casing, the inner part of which supports all of the aforesaid devices, substantially as set forth.

161 In a circuit breaker, the combination with a magnet core and two pole pieces, one rigid with respect to the core and the other pivotally mounted thereon, of terminal brushes and the rotary switch segment mounted in the single air gap-betweenthe pole faces of the said pole pieces. 4

17. In a.circuit bneaker, ablowout-magnet having a core and a pole piece-fixed withrespect to the core, and a second pole piece movably mounted on the coreand electric contact devices mounted in the single air gap between the pole faces of the said pole pieces.

In testimony whereof I afiix my signature, in presence of two witnesses.

. FRANK L. SESSIONS.

Witnesses: a l

N. Gr. Nn'rHo, C. E. WAXBOM. 

